Cambridge eased any growing relegation fears by thumping rock bottom Carlisle to move six points clear of the bottom four.
The U's can expect a much tougher test against Bolton, although the fact seven of their 10 wins this season have come at home should give them hope.
Bolton battled back twice against Charlton to claim a point on Saturday, but Ian Evatt's side are faltering at just the wrong time and have slipped three points behind second-place Derby.
However, Wanderers do still have games in hand on all the sides around them, and can move level on points with the Rams if they win a league game at Cambridge for the first time since 1985.